Installation and Maintenance Manual for the Afridev Handpump

Installation and Maintenance Manual
for the Afridev Handpump
REVISION 2 - 2007
This manual has been prepared to cover installation and maintenance aspects of the Afridev
Handpump.
This document results from several years of work carried out by Water & Sanitation Program
(WSP) in partnership with SKAT – RWSN (former HTN), NGO’s, handpump field workers and
the private sector in several countries.
The experience gained in recent years has been incorporated into this Specification.
This Manual is intended to assist all users of the Afridev Handpump, especially to give a
guideline for the installation procedure and also for preventive maintenance.
Suggestions for improvements and requests for further information are welcome, and should be
sent to SKAT at the address given below.
First edition:
SKAT - HTN Publication, 1995
Revised edition:
2-2007 by Karl Erpf,
Drawings:
SKAT, St.Gallen,
Photographs:
Meera & Ceiko Pumps Ltd. Hyderabad, India, and SKAT, St.Gallen,
Copyright:
SKAT - RWSN
Provided the source SKAT - RWSN is acknowledged, extracts of this publication
may be reproduced.
Distribution: SKAT
Vadianstrasse 42
CH-9000 St.Gallen
Switzerland
Phone:
Fax:
E-mail:
or
URL:
+41 71 228 54 54
+41 71 228 54 55
[email protected]
[email protected]
http://www.skat.ch and http://www.rwsn.ch
1
Installation and Maintenance Manual
for the Afridev Handpump
Contents
Page No.
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4
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4
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9
1.0
Background of the Afridev Handpump Development
2.0
Pump Features and Options
3.0
Supporting Documents
Part 1
4.0
5.0
6.0
Installation of the Afridev Handpump
........................................................……………………….
10
4.1
General Comments ........................................................……………………..
10
4.2
Selection of Platform Type
.............................................……………………..
12
4.3
Material required for Platform Construction
......................……………………
17
4.4
Preparation for Grouting the Platform for a Borehole
4.5
Grouting the Platform
4.6
Curing of Platform
4.7
Hard Core Layer and Fencing of Platform
4.8
Soak pit
4.9
Disinfecting the Well
Platform Construction
..........…………………
18
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20
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23
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24
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24
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25
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26
Preparation for Handpump Installation
5.1
Decision on correct Cylinder Setting Depth
......................…………………….
26
5.2
Materials and Tools required for Installation of “Down Hole Components” …..
28
5.3
Preparation of “Down Hole Components”
......................………………………
28
5.4
Important Information for Jointing PVC-U Pipes
...........………………………
31
5.5
Preparation of “Above Ground Components”
......................………………….
32
.............................................…………………
33
6.1
Installation of “Down Hole Components” ......................………………………..
33
6.2
Installation of “Above Ground Components”
38
Handpump Installation Sequences
2
......................…………………..
Part 2
7.0
8.0
9.0
Maintenance of the Afridev Handpump
Preventive Maintenance
........................................................…………………….
45
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45
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46
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47
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47
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47
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47
7.1
Preventive Maintenance Checks of Handpump
7.2
Maintenance of Pump Surrounding
Maintenance of Handpump
8.1
Diagnosis of Handpump Problems
8.2
Tools and Spare Parts required for Handpump Maintenance
8.3
Procedure of Dismantling “Above Ground Components”
8.4
Dismantling Threaded Pumprods
..................................……………………..
48
8.5
Re-installing Threaded Pumprods
..................................……………………..
48
8.6
Dismantling Hook & Eye Pumprods
..................................……………………
49
8.7
Re-installing Hook & Eye Pumprods
..................................………………….
49
8.8
Dismantling and Re-installing FRP Pumprods
.......................………………..
50
8.9
Re-assembling “Above Ground Components”
.......................………………..
50
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51
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51
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53
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55
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55
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56
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58
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61
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63
Repair of Handpump
9.1
Removal of the Rising main
9.2
Repair of the Rising main pipe
9.3
Fishing of Dropped Handpump Parts
10.0 Recording of Interventions
Annexes:
I
Trouble Shooting Chart for AFRIDEV Handpumps
II
List of Spare Parts for AFRIDEV Handpumps
III
Replacement Interval of AFRIDEV Wearing Parts
IV
Correct Storage of AFRIDEV Handpump Components
V
Examples for Recording of Interventions
………………………………………
66
VI
Drawings of Fishing Tools for dropped Handpump Parts ……………………..
70
VII
Technical Drawings of Repair Sockets
………………………………………….
74
3
Installation and Maintenance Manual
for the Afridev Handpump
1.0 Background of the Afridev Handpump Development
The Afridev started life in Malawi in early 1981. From the start, the aim was to produce
a deep well handpump that was very easy to maintain at village level and could be manufactured
in countries like Malawi, where industrial resources are limited. The Maldev pump head went into
production in early 1982, and was a significant step forward in head design, with the users'
needs given first priority.
Early in the field-testing of Maldev pumps, the ball bearings caused problems and the first
Afridev pump head, which uses plastic bearings, was installed in Malawi in late 1982. Major
efforts to resolve the "bearing problem" continued up to early 1985, when a plastic bearing
design was finalised.
The focus of Afridev development shifted to Kenya in early 1983, although testing continued
in Malawi. Important contributions were being made by field workers in several East African
countries, as well as by experts from organisations in Europe, who provided specialist advice or
laboratory testing facilities. International handpump design meetings were held in Kenya in late
1984 and early 1986, and throughout this period design and testing of pump heads, cylinders,
rods and rising mains continued. At all times, the primary objectives were absolute simplicity of
maintenance, and minimum quality control requirements to simplify manufacture.
Plastics research and development has played a vital role in the success of this project, of which
the outcome is the Afridev pump system.
The Afridev Handpump is manufactured in several developing countries in Africa & Asia.
It is demonstrating that village men and women can maintain deep well handpumps, can be
locally produced and can still be affordable and reliable.
2.0 Pump Features and Options
In the following pages you will find an overview of the pump features and the options available
4
5
Afridev Handpump
List of options available for this pump type.
Options
A
B
C
D
Pump head
type
Pump head with short
spout: (30 cm)
drawing No. B2003
Pump head with long
spout: (58 cm)
drawing No. B2003
---
---
Pump stand
type
Pump stand with
3 legs:
drawing No. B2050
Pump stand with
bottom flange:
drawing No. B2055
---
---
Rising main
arrangement
PVC-U Rising main
with “Bell ends”:
drawing No. A2099
PVC-U Rising main
with ”Sockets”:
drawing No. A2119
---
---
Cylinder
arrangement
Brass plunger and
Plastic footvalve:
drawing No. A2070
Brass plunger and
Plastic footvalve:
drawing No. A2257
Brass plunger and
Brass footvalve:
drawing No. A2296
---
Pumprod
arrangement
MS- Pumprods,
threaded connectors:
drawing No. A2206
SS- Pumprods,
threaded connectors:
drawing No. A2209
SS- Pumprods,
“Hook & Eye” conn.
drawing No. A2110

Explanations:

not any longer recommended

not recommended when PH value is

6.5
Abbreviations:
PVC-U
Polyvinyl Chloride (unplasticized)
MS
Mild Steel
SS
Stainless Steel
FRP
Fibre Reinforced Plastic
Example:
Possible composition of a selected Afridev Handpump:
Pump head type
Pump stand type
Rising main arrangement
Cylinder arrangement
Pumprod arrangement
A
B
A
A
D
For more clarification see the following 3 pages!
6
FRP- Pumprods,
Brass connectors:
drawing No. A5889
7
8
3.0 Supporting Documents
a)
b)
c)
d)
e)
f)
g)
h)
Afridev Handpump Specification, Revision 5-2007,
Afridev Handpump, Injection Moulding Guidelines, Revision 1-1999,
Moulding Guidelines for the Production of Rubber Components, Revision 1-1999,
Afridev Handpump, Mould Drawings for Rubber Components, Edition 2003,
Afridev Handpump, Packing Guidelines, Edition 1992,
Afridev Handpump, Quality Control Guidelines, Revision 1-2000,
Platform Design for Handpumps on Boreholes (Construction Guide), Rev. 1-2008,
Platform Design for Handpumps on Dug wells (Construction Guide), Rev. 1-2008,
9
Part 1 Installation of the Afridev Handpump
4.0 Platform Construction
4.1
General Comments
Sustained safe drinking water supply and sanitation facilities are essential to improve the living
conditions of the rural population. The provision of safe water helps to combat water borne
diseases and improves community health in general. Benefits of a safe water supply can reach
far beyond considerations of public health and have a positive influence on the general well
being, economic status and quality of life in a community.
4.1.1 Protection of Water Source
If a well site is chosen and the well drilled (or dug) into the ground at a site which is elevated and
away from water logged areas during the rainy season, the water which percolates from an
underground aquifer into the well should be pure enough to drink.
However, a water point obviously attracts a great deal of human contact. This is a potential
source of contamination and should be protected against. The safety measures are as follows:
4.1.2 Well Siting
a)
b)
c)
d)
The well should be in an elevated place, so that during the rainy season the water will run
away from it, rather than into it.
It should be at least 40 meters away from a latrine and uphill of the latrine.
It should be at least 30 meters away from a cattle kraal, and uphill of the kraal.
It should be well away from any depressed area in the ground, such as hollows that are used
for rubbish tipping, hollows that are used for brick making or any other areas where water
might collect.
10
4.1.3 Hygiene Education and Water Supply
Throughout the water supply process, it is vital to bear in mind the important linkages between
health, hygiene education and water. An awareness of the intimate relationships between these
factors should be made clear to all water users.
Before the arrival of a new or improved water supply system, the water users of a village should
receive hygiene training with regard to the collection, storage and use of water.
For example, the transmission of diseases through contaminated water may not be understood in
the community.
Cleanliness in the area of
the water point is an important
factor in the overall impact of
the introduction of a new or
improved facility.
If the surrounding area is not
kept clean and free of animals,
debris, waste and stagnant
water, the water point could
become a hub for the
transmission of many
infectious diseases.
In this respect, the ability of
the community to manage
the system and ensure
regular cleaning of the
water point is vital.
4.1.4 Platform Design
If the area around a well is allowed to become dirty, and waste and stagnant water is allowed to
accumulate, it will become a source of infection for the users. Standing in bare feet in stagnant
water or mud is a serious health risk in the tropics since the open water provides an ideal
breeding ground for many types of parasite and/or disease carrier. Awareness of the direct links
between hygiene and water must start at the collection point, otherwise the possible benefits
from an improved water supply will be lost.
The construction of a platform (or slab) at the wellhead is an important contribution to the general
hygiene in a community. In addition to discouraging the accumulation of stagnant water at the
surface, the slab will help to prevent the contamination of the well through the infiltration of dirty
water back into the aquifer.
The following points are important:
a) The slab surrounding the water point
should be made as wide as possible
from properly made reinforced concrete
of good quality.
The water outlet (spout should be
placed in the centre of the slab, so that
it collects the spill water, which then can
run away thorough the drainage channel.
11
b) All surfaces should slope towards
the drainage channel and the edges
of the slab should be raised.
c) The slab should be well reinforced
with steel wire, to prevent cracking.
Dirty water can pass through cracks
in a poorly constructed slab and
contaminate the well beneath.
The shape of the slab is not as
important as its capacity to drain
water away from the well as quickly
as possible and to ensure
wastewater dispersal in a hygienic
manner.
Where possible, the drain can lead
to an area of vegetation, such as
banana plants or a vegetable garden.
If this is not an option, a soak-pit can
be built or a trough for watering
livestock can be provided.
It is important that construction of the
slab does not commence until the soil
around the well, which was disturbed
by the construction activities, has had
an opportunity to settle properly.
4.2
Selection of Platform Type
Consultation with the community is a must before a decision is taken on the platform layout.
In the following three pages you will find typical platform designs for handpumps installed on
boreholes or on dug-wells. These are indicative layouts and can be modified to suit communities’
needs, which may include the following:
a) Facilities for washing clothes,
b) Facility for bathing,
c) Trough for cattle watering,
d) Collection of water for small-scale irrigation etc.
12
13
14
15
4.2.1 Fencing of Water Source
In addition to constructing a slab, it is important to erect a good fence around the water point.
This can be done immediately after the construction of the well is finished, and should give enough
space to operate the handpump.
The advantages of fencing are that it serves to define quite clearly, for the whole community, the
area of the well and it keeps animals away from the wellhead. In some cases, it may be necessary
to have a gateway to keep out smaller animals such as dogs and goats.
The fencing can be made of suitable local materials like wood or stones. Problems of replacement
and repair can be avoided altogether, by using a living hedge as fencing.
Whatever type of fencing is used, it is important that access by the well users is guaranteed.
16
4.3
Material required for Platform Construction
4.3.1 Recommended Masonry Tools for Platform Construction
Item
Shovel /Scoop
Spade
Pick or Crow bar
Mason’s trowel
Levelling plank (0.5 and 2 m)
Rubber bucket (for concrete)
Steel bucket (for water)
Measuring tape (3 m)
Spirit level
Platform shuttering (Steel form or wooden material)
Tamper sticks (for removing trapped air)
Approx. Quantity
3 nos
1 no
2 nos
2 nos
1 each
4 nos
2 nos
1 no
1 no
1 no
1 no
4.3.2 Materials and Consumables for Platform Construction (Borehole)
Item
Washed Sand (without too much mud content)
Gravel (approximately Ø20 mm)
Cement (bags of 50 kg)
Burned bricks (3” x 4.5” x 9”)
Wire netting for platforms (50 x 50 x Ø3 mm)
Reinforcement bars for dug-well covers (Ø6 - 8 mm)
Binding wire for connecting reinforcement bars
Hessian cloth for curing of platform
Pump stand (for stand with 3 legs)
Anchor assembly (for stand with bottom flange)
Wooden board (protection against contamination)
Approx. Quantity
2 cubic meters
4 cubic meters
8 bags x 50 kg
100 nos
1.7 x 1.7 m
15 m
10 m
to cover platform
(1 no)
(1 no)
1 no (bolted on flange)
4.3.3 Materials and Consumables for Platform Construction (Dug-well)
Since most dug-wells differ in size, the quantity of material required for the construction of
a platform including wellhead and well cover has to be calculated.
4.3.4 Materials and Consumables for Soak Pit Construction
Additional materials used for the construction of a soak pit:
sand, pebbles, stones of different sizes, bricks, bamboo matting, Hessian cloth or jute-bags.
17
4.4
Preparation for Grouting the Platform for a Borehole
If the protruding well casing is not already closed with a top cap, cover it with a clean
piece of a cloth or a plastic bag and secure it with a string. This cover should remain in place
until the pump stand is finished and the handpump installation takes place.
Step by step manufacturing of the platform is explained in the following sequences:
4.4.1 Setting out
After the decision has been made,
in which direction the handpump
has to be placed, the first peg is
placed 35 cm from the protruding
casing pipe. This peg should take
advantage of the natural slope of
the area i.e. it should be sited
downhill of the casing if at all possible.
This peg is the centre of the platform and from this position the Centre lines (CL) are set and
marked with pegs.
Clear the platform construction area of bush and surface irregularities.
4.4.2 Marking Foundation
Make a loop at the end of a string
and place it over the peg in the centre.
Attach another peg at the required
distance (75 cm) to the other end and
mark the inner circle (radius 75).
Afterwards, use the same system as
above to mark the circle with radius 100.
Mark all other measurements as given
in the picture.
For better marking, small pegs or short branches can be placed in 5 to 10 cm distances along
the marked line.
4.4.3 Digging Foundation Trenches
Dig the trench for the foundation
carefully and make sure that the
marked outline of the platform does
not get damaged during digging.
The foundation trench is finished as
soon as the depth is a uniform 40 cm,
which can be checked from any point
of the prepared surface.
18
4.4.4 Placing the Pump stand
It is important that the pump stand,
which is placed over the protruding
casing pipe is at the correct height
and is absolutely vertical.
The pump stand needs to be secured
well with stones or wooden struts, so
that it does not change its position
during the grouting process.
Remove the cover of the protruding casing pipe. Place the pump stand over the pipe and
check the centricity of the casing inside the standpipe.
Make sure that the flange of the pump stand is pointing in the right direction.
Put stones underneath the legs of the pump stand, until the flange is at the required height
of 66 to 70 cm from the platform base (or 106 to 110 cm from the floor of the excavations).
It is important to check that the flange of the pump stand is completely horizontal in all directions.
Check this using a spirit level and adjust the pump as required. To secure this position, use
stones or wooden struts.
4.4.5 Final Preparation prior to Grouting of Platform
Before starting with any concrete work, check whether all preparation work is completed,
so that the different cement work (wet in wet system) is not interrupted too long. It is very
important that enough raw materials have been collected to complete the following steps
without interruption before any mixing of concrete should start.
a) Cement, sand, gravel, bricks (and enough water),
b) Reinforcement bars or netting,
c) Shuttering material (or form work) for the platform ring and drainage channel,
d) Steel bars for connecting platform and drainage channel (2 off)
Prepare enough concrete
for filling the entire
foundation space up to
the ground level.
The mix should be 1:2:3.
This means:
1 volume of cement,
2 volumes of sand and
3 volumes of gravel.
Mix the cement, sand
and gravel thoroughly,
before water is added.
For grouting sequences
see the following pages.
19
4.5
Grouting the Platform
4.5.1 Fill Foundation with Concrete.
Before the concrete is compacted,
check again the flange for
horizontality and adjust if necessary.
Compact with a vibrator or by hand
(use a tamper) to remove trapped air.
4.5.2 Reinforcement of Platform and Placing of Shuttering
Place (and bind together) suitable
reinforcement bars on the platform
area, or lift preformed netting over
the pump stand.
Support the reinforcement with small
stones or with the help of cement
cubes in order to lift it to the required
height.
The position of the reinforcement
should be between 2 to 3 centimetres
below the finished cement surface.
Place the shuttering (formwork) and
support it with pegs or heavy stones.
4.5.3 Casting of Well Platform and Operation Platform
Prepare enough concrete for casting
the platform.
Fill the platform with a concrete layer
of 12 cm and compact by tamping.
After a curing time of approximately
1 to 2 hours, the shuttering can be
removed carefully.
20
Prepare enough mortar for the final
layer with slope and bricks for
constructing the ring of the platform.
Now the final layer for the slope
can be applied. Make sure that the
slopes are in the right direction.
After a short while of applying the
final layer (15 to 30 minutes), the
bricks for the ring of the platform
can be placed.
4.5.4 Casting of the Drainage Channel
During the curing time of the well platform, all work for casting the drainage channel can be
started. Proceed as follows:
Dig the required trench for the
drainage channel and make sure
that the 2% gradient on the
downward slope of the platform
continues right to the end of the
channel.
Place and secure the formwork
of the 6m long drainage channel.
If required, place the
reinforcement bars or netting.
Prepare sufficient concrete and
cast a layer of 12 cm.
After a curing time of approx. 1 to 2 hours, the shuttering can be removed carefully.
Prepare mortar for final layer and enough bricks for the two rims on drainage channel.
The bricks can be placed 15 to 30 minutes after the final layer has been applied.
After the bricks are in position, all
final work (like finishing and
smoothing all surfaces of the
platform and the drainage
channel) can start.
Make sure that all top corners
of the platform ring and the rims
of the drainage channel are made
with chamfers and a radius is
applied between the platform and
the ring.
21
4.5.5 Grouting of Platform for Pump stand with Bottom Flange
When grouting of a platform for
the Pump stand with Bottom
Flange, the normal procedures
as described before can be
followed.
The only difference to the
platform for the pump stand with
legs is that the Bottom Flange
is placed in top of the slab and
only the Anchor assembly needs
to be grouted.
Therefore the foundations at the
casing pipe can be made more
shallow. It is also advisable to
raise the surface of the flange by
approximately 3 cm, to make it
exactly level (see picture).
When placing the anchor assembly for grouting, make sure that the anchor bolts are protruding
the top face of the raised surface by 4 cm.
4.5.6 Grouting of Covers for Dugwells
Dugwells need to be closed by a strong
cover, on which the handpump can be
installed.
Form a ring of bricks according to the well
diameter and cover the whole surface with
with plastic sheets.
Place the anchor assembly, a wooden plug
(forming the “Manhole”), two handles and
the reinforcement bars, and fix the whole
assembly with binding wire prior to grouting.
Grouting procedure and curing
time etc. is comparable to the
construction steps of the
platforms.
For exact positioning of the
anchor assembly and the plug
for the “Manhole”, see sketch at
the left side.
For more details see also
“4.5.5 “Grouting of Platform
for Pump stand with Bottom
flange”.
22
4.6
Curing of Platform
Following the final touch of the platform, protection is required from being destroyed:
As soon as all final work is
completed, all cement work
needs a curing time of at least
one week.
During the curing period, the
platform needs to be watered
regularly, so that it never gets
dry.
Partitions made of clay or other
material blocks the water from
being drained after watering.
Before leaving the water point,
cover platform and drainage channel with thorn bush, so that it is well protected from being
destroyed by passing people or by animals attracted by the water.
Please note:
For more information on platform construction, please consult the following SKAT Publications:
a) Platform Design for Handpumps on Boreholes (Construction Guide), Rev. 1-2008,
b) Platform Design for Handpumps on Dug wells (Construction Guide), Rev. 1-2008,
23
4.7
Hard Core Layer and Fencing of Platform
4.7.1 Hard Core Layer around the Platform
A hard core layer should be placed around the platform. This acts as a protection of the
concrete platform and prevents spill water to create a swampy muddy area. Proceed as follows:
Mark the outside line of the hard
core layer and dig as much as
required, so that the brick or stone
layer is level with the ground
surface when finished.
Bricks or stones are placed on
mortar or sand and the joints are
filled with mortar.
4.7.2 Fencing of Platform
The entrance of the fence should
be able to be closed or be made
as narrow as possible, so that no
animal is able to enter the
well point (see also 4.2.1).
4.8
Soak pit
Construct a soak
pit if natural drain
is not available.
In the picture you
will see a typical
construction of a
soak pit.
Fill the excavated
hole with stones,
broken bricks,
gravel and cover
with sand.
To prevent that
sand is washed
away, fix a mud
pot (with holes at
the bottom) at the end of the drainage channel, so that the spill water can drain slowly.
24
4.9
Disinfecting the Well
As soon as the curing time is over and the platform is ready for installation of the handpump, the
well needs to be disinfected with chlorine.
Many of the diseases that are
common in the communal lands
are carried by water, especially
from unprotected wells, water
holes, rivers and dams.
Dysentery, diarrhoea and typhoid
can arise as a result of drinking
water that is infected.
The disease carrying organisms
found in the water can be
effectively killed by disinfecting
the water with chlorine.
Therefore it is recommended
to disinfect the well shortly
before the installation of the
handpump takes place. Proceed
as follows:
Mix 300 grams of bleaching
powder thoroughly in 15 litres
of water in a bucket and pour
the solution into the borehole.
The required dosage of
bleaching powder for dug-wells
is depending of the amount of
water stored in the well.
It is recommended to use
between 150 to 200 grams of
bleaching powder per cubic meter water for safe disinfection.
25
5.0 Preparation for Handpump Installation
5.1
Decision on correct Cylinder Setting Depth
5.1.1 Static Water Level (SWL)
One of the important factors for the cylinder setting is the surface of the water in a well, which is
called “Static Water Level” (SWL). The SWL can vary due to seasonal conditions (dry or wet
seasons) and therefore should be checked and recorded over a period of several years.
Such records would be important for the decision at what depth the cylinder should be placed.
Checking the depth of the SWL in a dug-well can be done through the manhole or a special hole
provided in the well cover, the same procedure is more difficult if an Afridev is installed in a
borehole. The pump head cover, the handle and the pumprods need to be dismantled, before
checking of the SWL can start.
5.1.2 Dynamic Water Level (DWL)
Apart from seasonal fluctuations, there are also fluctuations in the well itself because of pumping
water from the well. In order to check the drop in the water level (draw down) and to find the
DWL, test pumping on a new borehole should be done by the drilling crew.
For handpumps, the test pump
should be set for 1000 litres per
hour (maximum) in order to see
where the DWL is reaching.
These tests should be
continued for approximately
hours, in order to ensure the
correct DWL.
This figure is another important
factor for deciding on the best
setting depth of the handpump
cylinder.
(On marginal holes, pumping
rate might be reduced to 800
litres/hour.)
5.1.3 Other important factors
Any pump intake in a
borehole must be set
above the well screen
in fully screened well or
above any rock fissures
providing water in an
unlined well.
A pump intake above
the well screen or rock
fissures is minimizing
the turbulent flow of
water and therefore reduces the pumping of fines and silts.
Pumping water with a too high content of fines or silt is wearing the surface of the pump
cylinder and the plunger seals in an unacceptable rate.
If a pump cylinder is placed to close to the bottom of a borehole, silt and sand could build-up
and trap the pump in the hole.
26
5.1.4 Cylinder setting in Boreholes
Check the depth of the DWL and the depth where the well screen starts (information must
be available from the drilling crew). The start of the well screen should be considerably lower
than the DWL. If there were a large difference, it would be ideal to place the cylinder
approximately 1 meter above the well screen.
Check the SWL regularly, especially during the dry season, in order to avoid that the newly
installed pump is running dry. Should the cylinder setting depth be critical during the dry
season, add one length of riser pipe and one pumprod.
5.1.5 Cylinder setting in Dug-wells
The cylinder setting for dug-wells is not so critical, because the SWL can be checked
regularly through the manhole. It is advised to place the cylinder as such, that the suction
pipe is at least 0.5 meter above the well ground, to minimise pumping of silt and sand.
Should the SWL drop in the dry season to such a level that the pump is running dry,
increase the depth of the dug-well by some meters.
Adjust the rising main by adding additional riser pipes and pumprods.
27
5.2
Material and Tools required for Installation of “Down Hole Components”
5.2.1 Tools and Equipment
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
Measuring tape
Pencil / permanent marker
Hacksaw
Pocket knife
Rasp or coarse file
Sand paper 60 – 80 grit
Brush, flat 50 x 4 mm
Brush, flat 25 x 3 mm
White absorbent paper
Small bowl (Bakelite or tin)
marking exact length and square cutting line,
marking prior to cutting,
easy cutting of PVC-U pipes,
deburring of inside edges (inside chamfering),
chamfering the inside and outside edges,
roughening of jointing surfaces,
for outside application of solvent cement,
for inside application of solvent cement,
cleaning paper (or toilet paper),
for easy application of solvent cement,
5.2.2 Material
a)
b)
5.3
Cleaning fluid
Solvent cement
Carbon tetra chloride base,
Tetrahydrofurane base,
Preparation of “Down Hole Components”
5.3.1 Prepare a suitable working place not too far from the well point (place two logs for resting
the pipes in a clean place above the ground), preferably in a shady place.
5.3.2
Calculate all pipes needed for the required installation length and add a cylinder, a suction pipe,
the needed number of rising main centralisers and the top sleeve.
5.3.3
Slide all centralisers over the pipes until they rest at the beginning of the bell-ends.
One centraliser is placed at the end of the cylinder (use a little water for easy sliding).
5.3.4
Place all pipes and the cylinder with suction pipe neatly next to each other on top of the two logs
and clean all parts from dirt and dust.
5.3.5 The rope for supporting the rising main during the jointing process needs to be stretched out on
the ground and straightened (removing all kinks). Then the two ends should be brought together
to find the midpoint of the rope, where a knot needs to be made. Place the rope neatly on the
ground near the well platform and make sure that it is in a clean place, to avoid contamination of
the well during installation.
5.3.6
Mark each pipe end with a pencil
or permanent marker at 115 mm
(the position where the bell-end
will rest after jointing).
28
5.3.7
If one of the pipes needs to be shortened, mark the exact position (a line around the whole pipe)
and cut along the line with the hacksaw, remove the burrs with a knife.
5.3.8
Check all pipe ends for exact chamfer sizes, make chamfers if necessary with the rasp or coarse
file (Note: both inside and outside chamfers are required, see sketch).
chamfered 5 x 15°
(inside and outside)
all sharp edges rounded
5.3.9
All pipe ends (outside) up
to the marked line and also
all bell-ends (inside) need
to be slightly roughened with
sand paper until the surface
appears matt.
29
5.3.10 Then the roughened surfaces
need to be cleaned properly
with the cleaning fluid to
ensure that they are free
from any oil or grease (use a
new paper with cleaning fluid
as soon as any dirt is visible
on the white paper).
5.3.11 Let the cleaned surfaces dry
for approximately 5 minutes
and make sure that nobody
touches the prepared surfaces
with their hands.
5.3.12 Pass one end of the rope through the 10 mm hole of the suction pipe until the rope stops
because of the knot. A second knot needs to be made at the other side of the suction pipe,
so that the rope is fixed and cannot be pulled out to either side.
5.3.13 Clean the apron of the pump point, and
prepare all the tools that are needed for
the application of the solvent cement and
the jointing procedure.
5.3.14 Fix two bolts in two opposite holes of the
pump stand flange so that it is possible to
tie the rope to them (see picture of 6.1.4).
Note: a) Well chamfered and rounded pipe
b)
a)
ends prevent the layer of cement
from being stripped off, as the pipe
is inserted into the bell-end.
The mark of the jointing length
(115 mm) on the pipe ends makes
it possible to check afterwards
whether the pipe has been inserted
to the full extent of the bell-end.
The bell-ends of the standard pipes
are slightly tapered and designed
as such that the pipe cannot be
inserted dry into the bell-end.
This will only become possible once
the cement has been applied.
Do no attempt to make a joint that does not achieve an interference fit when dry.
This can be checked by inserting the spigot into the bell-end before cement is applied – if
the pipe end (spigot) slides fully into the bell-end, it will not be possible to cement this joint
satisfactorily, so this pipe should not be used here.
30
5.4
Important Information for Jointing PVC-U Pipes
5.4.1 Solvent Cement Jointing:
Solvent cement jointing (welding process) of PVC-U pipes offers a simple and quick means of
construction high integrity leak-free joints. Correctly made joints are stronger than the pipe itself.
The solvent cement operates by chemically softening the outside of the pipe end (spigot) and the
inside of the bell-end (socket). Joint integrity is greatly reduced if these surfaces are not
absolutely clean and properly prepared.
This fact calls for adequate technical knowledge, clean working conditions and exact preparation
procedures. The jointing instructions (see 5.1 Installation of “Down Hole Components) are
intended to assist all those who are using this technique for the installation of PVC-U rising
mains for handpumps.
5.4.2 Clean Working Condition:
As mentioned before, a clean working environment is necessary for receiving strong and leakfree pipe joint results. Without too much of a hassle, the working condition around the well point
can be organised as such that clean working is possible. This includes:
a) placing PVC-U pipes on logs for preparing/cleaning of joints (in a shady place),
b) Placing pumprods on logs near the well (beware of dirt/sand entering threads),
c) Cleaning material (Fluid & Toilet paper) and jointing material (solvent cement, bowl &
brushes) in a shady, clean and dry place (see also “Tips for working with Solvent Cement”,
page 37).
5.4.3 Organised Working:
Since it is of great importance that each jointing process has to be completed within a short
period (recommended is 1 minute), the tasks of the installing personnel have to be organised.
In order to have sufficient time, it is advisable that the application of solvent cement is made by
two persons, one for the pipe ends and one for the bell ends.
3 people are required for pushing the pipes together; one for pushing the bell end over the pipe
end and two people for gripping the pipe end, so that stretching of the supporting rope can be
reduced.
One person is responsible for the time; he gives the command for staring of solvent cement
application, for pushing the pipes together, for keeping the required curing time and he also
informs the crew when lowering of the joined pipes can start.
5.4.4 Excessive Applications of Solvent Cement:
Do not use excessive solvent cement when preparing for a new joint. A too thick layer of solvent
cement will be scraped from the surface when the pipes are pushed together and will lead to a
deposit inside the bell-ends.
Large deposits inside the bell ends must be avoided as these can weaken the wall of the rising
main pipe or might build up as much that the inside diameter of the pipe will be reduced and the
plunger will not be able to pass through.
31
5.4.5 Curing Time for new joints, before next jointing can start:
a) Every new pipe joint during installation:
For any new pipe joint, a curing time of at least 5 minutes is required, before the assembled
pipes can be lowered by the ropes and a next joint can be started.
b) Last joint at the end of the rising main pipe (Top sleeve):
The curing time for the top sleeve should be at least 20 minutes, before the completed rising
main is lifted for tightening the rope ends to the cone plate (see also 6.1.14).
c) Complete rising main before pump is allowed to be operated:
It is essential that the whole rising main be allowed to cure for at least 12 hours until
the maximum load applied can be taken by the joints (operation pressure, weight of
water column and stretching of the pipe due to the oscillating movement during
operation of the pump).
5.5
Preparation of “Above Ground Components”
5.5.1
Assemble the “bearing bush sets”
by pressing the bushes together by
hand (4 sets per pump).
5.5.2
Slip on one centraliser on each
pumprod.
5.5.3
Keep all prepared rods on a clean
place, preferably laid on a stand
made of two logs close to the
installation spot and make sure that
all threads are cleaned from sand
or mud.
5.5.4
Place all remaining pump components like pump cover and handle parts close to the installation
spot and keep the small components like bearing bushes, fulcrum- / hanger pin and all nuts and
bolts in the pump head cover.
32
6.0 Handpump Installation Sequences
6.1
Installation of “Down Hole Components”
Note: The joint should be completed in less than 1 minute from the time when the application of
cement begins.
6.1.1
Pour an adequate amount of
solvent cement into the small
bowl and apply a layer of
cement to interior surface of
the bell-end of the suction
pipe and a layer to the
cylinder (or spigot) end.
6.1.2
Place the end of the suction
pipe on the apron and insert
the cylinder in “one go” into
the bell-end of the suction
pipe.
6.1.3
Remove any surplus solvent
immediately with absorbent
paper.
6.1.4
After a curing time of at least
5 minutes, insert the suction
pipe with cylinder into the
pump stand and lower it so
that the cylinder top is
protruding by about 0.5 m.
Then tighten the two ropes
on the two prepared bolts
on the pump stand flange.
6.1.5
Apply solvent cement to the inside of the bell-end with the smaller brush and at the same time the
application to the pipe end of the protruding pipe should be made with the bigger brush.
The brush strokes should always be in an axial direction. Ensure that both jointing surfaces are
completely covered with a smooth and even layer of cement. (Application time should never
exceed 30 seconds for each surface.)
33
6.1.6
Bring the riser pipe into position
and push the bell-end immediately
“in one go” over the protruding pipe
until its end position.
Don’t twist the newly inserted
pipes anymore, as soon as they
are pushed together.
During this strong pushing
procedure, the cylinder or the lower
pipes needs to be supported by
hand (requiring at least 2 workers),
so that the whole force of the
“Push” is not taken by the fixed
rope alone.
6.1.7
Remove any surplus of solvent
cement immediately with
absorbent paper.
6.1.8
Allow the joint to set at least for
minutes before loosening the
ropes for lowering the pipe into
the position for the next joint.
6.1.9
When lowering the pipe, place
the rope into two opposite
grooves of the centralisers
and never support or hold the
pipe by hand (support only by
the two rope ends) since the
weight of the pipe should not
be taken by the newly made
joints.
34
6.1.10 As soon as the protruding
pipe is in the required
position for the next joint,
secure it by fixing the rope
to the bolts on the pump
stand flange.
This procedure needs to
be repeated until the last
pipe is connected.
6.1.11 As soon as the last pipe
is lowered, the steel cone
is inserted and laid to the
top flange of the pump
stand.
Then the rubber cone has
to be slid over the pipe, so
that the pipe end is
protruding by approximately
100 mm.
35
6.1.12 Clean the protruding pipe end again
with cleaning fluid and as soon as it
is dry, apply solvent cement to the
pipe (80 mm depth) and also to the
inside of the top sleeve.
6.1.13 Allow the jointed top sleeve to set
for at least 20 minutes, before the
rubber cone and the steel cone
are adjusted.
6.1.14 After the setting time, one or two
persons should lift the complete
rising main assembly by the steel
cone, while a third person starts
to connect both rope ends to the
eyes of the steel cone with two or
three securing knots.
6.1.15 Cut the rope ends, but leave at
least 2 m excess length for each
rope end (this makes it easy for
connecting another rope for easy
removal, in case the rising main
assembly needs to be pulled out
for repair).
6.1.16 Insert the rope ends into the pipe
of the pump stand or the casing
pipe, lower the whole rising main
assembly onto the pump stand
flange and remove the bolts from
the flange.
36
6.1.17 Move the steel cone
so that all four holes
of the cone plate and
the pump stand flange
are matching.
6.1.18 Cover the hole of the newly installed rising main pipe to prevent playing children from dropping
dirt or stones into the well and let the joints cure for at least 12 hours.
Tips for working with Solvent Cement:
a)
b)
c)
d)
e)
f)
g)
h)
Remove any skin, which may have formed on the cement in the tin.
Stir the solvent cement thoroughly.
Solvent cement should have the correct consistency. It should run smoothly from the bottle
into the small bowel. Cement that no longer runs smoothly is unusable. Therefore never
expose solvent cement to the sunlight and store it in a dry and cool place. (The same applies
also to the cleaning fluid.)
Pour only the approximate amount of solvent cement into the small bowl that is used for the
next joint and close the lid of the tin or the bottle immediately after pouring (to prevent the
solvent evaporating).
When applying solvent cement to the inside of the bell-end hold the pipe horizontally and use
the smaller brush. Work the cement in well with brush strokes in the axial direction until it
forms an even layer.
Do not use excessive solvent cement and do not dilute or add anything to the solvent
cement. Excessive deposits inside the bell-ends must be avoided as these can weaken the
wall of the pipe.
Use a shelter to keep jointing surfaces dry in wet weather.
Clean the brushes and the bowl with dry absorbent paper after use. Brushes must be dry
and flexible before being re-used.
37
6.2
Installation of “Above Ground Components”
6.2.1
Install pump head on stand
assembly and tighten bolts
fully.
Now the pump is ready for the
installation of the plunger with
the pumprods.
6.2.2
Attach plunger rod with the
plunger and check that the
bobbin and the cup seal (or
U-seal) are in the correct
position.
6.2.3
Threaded Pumprods
Connect first pumprod to the plunger
rod and insert it into the rising main
pipe.
Lower the pumprod assembly and
place the Resting tool on the Pump
head, so that the hexagonal connector
is resting in the keyway of the limiters
(see picture beside).
6.2.4
Lift the pumprod assembly slightly to
release the resting tool, so that the
newly fastened connection can be
lowered.
As soon as the connection has
entered the pump head, the resting
tool can be placed again for preparing
the next connection.
6.2.5
Connect all following pumprods and
make sure that all connections are
tightened securely.
6.2.6
After the last rod (Top rod) has been
fastened, lower the completed
pumprod assembly until the plunger
is sitting on top of the footvalve.
38
6.2.7
Pumprods with Hooks & Eyes
Connections are made by inserting
the hooks horizontally into the eyes.
Turn the horizontal rod upwards, so
that the connection is tight and the
rods are exactly in line.
6.2.8
Make sure that the free-hanging
pumprod assembly is gripped
securely by 2 or 3 people, so that it
does not fall into the rising main
assembly during this installation
procedure.
6.2.9
Connect all pumprods as described
until the plunger is sitting on top of
the footvalve.
6.2.10 FRP Pumprods
The total weight of FRP Pumprods
is about 1/3 of the conventional
steel rods and in addition, they are
also flexible.
Therefore it is easy to connect them
outside of the borehole and lower it
as a completed assembly.
6.2.11 To determine at what point the top
rod needs to be cut, so that the
pumprod assembly has the required
length, proceed as follows:
a)
Let the pumprod assembly rest
fully, so that the plunger is
sitting on top of the footvalve.
b)
Insert one hand into the pump
head and grab the protruding
pumprod at the top end of the
rising main pipe and use the
thumb for keeping the exact
measurement.
c)
Don’t loose the grip of the pump
rod, when with the help of two or
three other people, the complete
pumprod assembly is lifted by
approximately one meter.
39
6.2.12 As soon as the hand is outside
the pump head, mark the exact
position of the thumb with a
permanent marker.
mark
6.2.13 After marking, lift the pumprod
assembly as far as to the next
connection and disconnect the
top rod.
6.2.14 Cut the top rod at the mark and
connect it again with the
pumprod assembly.
6.2.15 Slip on flapper on the pumprod
and fix the rodhanger assembly.
Make sure that the rod is inserted
to the full extent and that the
hexagonal bolt is tightened
securely.
6.2.16 Insert the spanner handle into
the bush on top of the rodhanger
and lower the complete pumprod
assembly, so that the spanner
handle is resting in the two slots
provided in the pump head.
40
6.2.17 Prior to connecting the handle
front assembly, assemble one
bearing set with the fulcrum pin
and insert it into the fulcrum
housing of the handle front.
From the other side attach the
second bearing set and make
sure that lugs are located in the
slots of the fulcrum housing.
6.2.18 Adjust the lock pins of the
fulcrum assembly and the two
lugs of the bearing bush inner
to the correct position (see
sketch).
Then, the handle front can be
inserted carefully into the slots
of the fulcrum bracket.
6.2.19 Insert the handle front fully
and fasten the special nuts
of the fulcrum pin by hand.
41
6.2.20 Prior to the next step, make
sure that the handle is held
securely in a horizontal position,
in order to avoid pinching of
fingers of the person who is
assembling the rod housing.
6.2.21 Assemble one bearing set with
the rodhanger pin and insert it
into the rodhanger assembly.
From the other side attach the
second bearing set and make
sure that lugs are located in
the slots of the hanger bush.
6.2.22 Adjust the lock pins of the
rodhanger assembly and the
two lugs of the bearing bush
inner to the correct position
(see sketch), before the handle
front can be lowered carefully.
6.2.23 If additional adjustments of
lugs and pins are required
during insertion into the slots
of the handle front, please
take care of your fingers.
6.2.24 Push down the handle to its
lowest position and remove
the spanner handle from the
lug of the rodhanger assembly.
42
6.2.25 Prior to fastening the nuts of
the fulcrum- and hanger pin,
make sure that they are in
correct position. Tighten nuts
securely.
6.2.26 Insert the handle rear assembly
into the handle front assembly
and tighten adjustment bolt
securely.
Balancing of the handle can
only take place, once the
rising main pipe is completely
filled with water.
A correctly balanced handle
remains in horizontal position when left free.
6.2.27 Operate the handle till the water flows out of the spout.
The number of strokes required until full flow is reached, is determined by the installation depth
of the cylinder (the installation depth divided by the maximal handle stroke indicates
approximately the number of full strokes required).
Due to the slightly bigger diameter of the riser pipes, about six full strokes are required for
lifting the water by 1 m.
6.2.28 Initially the first water might be turbid and smelling from chorine, but after 15 to 30 minutes of
operation it should become clear.
6.2.29 Now the following checks should be carried out:
a) All nuts and bolts are well secured,
b) Effort required to operate the pump is normal,
c) No leakage in the rising main (wait for 5 minutes to see whether water in the rising main
assembly is receding,
d) Water discharge (approx. 40 strokes per minute) is above 16 litres,
e) Existence of identification mark of the support agency (painted or stamped).
6.2.30 Fill in the installation
card (see Annex 5a).
A copy of the card
should be given to
the users committee
or to the handpump
caretaker.
6.2.31 Fix the cover and
tighten the cover bolt.
43
6.2.32 Inform the caretakers and
users to wait until the next
day and then pump for
approximately 30 minutes,
to make sure that the
bleaching powder solution
is pumped out completely.
6.2.33 Check whether caretakers
or users are aware of the
preventive maintenance
required.
6.2.34 Check whether caretakers
or users are informed where
to get spare parts and whom
to contact, if the pump needs
repair.
44
Part 2
Maintenance of the Afridev Handpump
7.0 Preventive Maintenance
Every pump owner, caretaker or the user committee is responsible for the preventive
maintenance of the water point (handpump including surrounding) and therefore is entitled to
receive regular training from the supplier of the handpump.
Preventive maintenance means regular check-up of the handpump at a fixed time interval and
changing of spare parts before they are fully worn.
As an example: if the estimated lifetime of a plunger seal is one year, the plunger seal will be
changed after a period of one year even if it is still functional. If during a preventive maintenance
check, footvalve leakage is noticed, the caretaker will carry out repairs in the footvalve even
though the pump has not broken down.
Such interventions help in preventing the sudden failure of the pump.
7.1
Preventive Maintenance Checks of Handpump
7.1.1 Weekly checks:
Check that the flange bolts and nuts are tight.
Check that the Fulcrum pin nuts and Hanger pin nuts are tight.
7.1.2 Monthly checks:
Check if any fasteners or parts in the pump head are missing. If so, replace the parts.
If any unusual noise is noticed, check reason for the same and take corrective actions.
Check if the pump stand is shaky during operation. If yes, the stand is loose in the
foundation and contamination of the well can take place. Take corrective measures to repair
the foundation.
Check if there is leakage in the pump. If more than 5 strokes are required before water
comes out from the spout, it means the pump is leaking beyond an acceptable limit.
This needs to be attended to. It may be necessary to replace bobbin / footvalve O-ring or
attend to a leaking joint in the rising main. For attending to a defect in the rising main you
may need the help of a skilled mechanic. The special leakage test can be conducted as
described below.
Carry out a “Leakage- and Discharge Test” (see 7.1.3 and 7.1.4 below).
7.1.3 Leakage Test
Proceed as follows:
a) Operate the pump handle until water is flowing from the spout.
b) Stop operating the pump handle for approximately 30 minutes.
c) Then operate the handle and count exactly how many strokes required until the water is
starting to flow again.
If more than 5 full handle strokes are required to make the water flow again, there must be a
leakage in the rising main or the footvalve.
Leakage mostly occurs because of worn bobbin or o-ring of the footvalve, disconnected rising
main joints or perforated or cracked riser pipes.
Report this problem immediately to the pump mechanic and ask for rectification!
45
7.1.4 Discharge Test
Proceed as follows:
a) Operate the pump handle until a continuous water flow has been achieved (pump ratio
approximately 40 full strokes per minute).
b) Place a bucket in the continuous water flow for exactly one minute.
c) Take the bucket off the water flow and check the amount of water drawn.
The water collected should be generally not less than 15 litres.
If the discharge is less then 10 litres for 40 full strokes, there might be a problem with the
bobbins or the cup seal.
Report this problem immediately to the pump mechanic and ask for rectification!
7.2
Maintenance of Pump Surrounding
Handpumps with platforms offer a good protection, because they seal off the well from external
sources of contamination. However, even when handpumps are fitted, contaminations can still
pollute the well through:
a) Cracked platforms and drainage channel,
b) Stagnant water near the well,
c) Animals (and human) excrements too close to the well (no fence),
d) Waste and other sources of contamination too close to the well.
It is the important task of the Handpump Caretaker to:
1.) Check the platform for cracks and do the necessary repair,
2.) Eliminate stagnant water by filling the dents and holes with earth,
3.) Maintain the fence around the water point, so that no animals have access,
4.) Keep the surroundings clean and tidy at all times,
5.) Instruct the pump users how to use the pump and how to keep the pump
surroundings clean.
(See also 4.1.2 Well Siting and 4.1.3 Hygiene Education and Water Supply.)
46
8.0 Maintenance of Handpump
The handpump is like any other mechanical device and needs maintenance to keep it in good
working condition. It has been observed that the maintenance in community handpumps is very
often “Breakdown-based”.
In the absence of preventive maintenance, sudden breakdown of handpumps and disruption in
water supply do occur. The danger of abrupt breakdown of the pump can be minimized if
preventive maintenance is carried out.
The steps involved in maintenance are to:
a) Understand the cause for a problem and determine the remedy need,
b) Dismantle the pump as necessary,
c) Assemble the pump after replacing defective components,
d) Record details in the “Maintenance card” (see Annex V b).
8.1
Diagnosis of Handpump Problems
To identify the cause for a problem and remedy needed, please refer to the “Trouble Shooting
Chart (Annex I.) This chart lists general operational problems, their causes and remedies.
8.2
Tools and Spare Parts required for Handpump Maintenance
8.2.1 The basic tools required for handpump maintenance are:
a) Spanner for M16 hexagonal bolts and nuts (B2160),
b) Fishing tool for retrieving the footvalve (B2150).
For deep installations (between 30 to 45 m) with a heavy load of the pumprod assembly, the use
of the Resting tool B2415 & Connecting tool B2420 is advisable (this is for threaded rods only).
8.2.2
The “List of Spare Parts for AFRIDEV Handpumps” is given in Annex II (see also “Replacement
Interval of AFRIDEV Wearing Parts” in Annex III).
8.3
Procedure of Dismantling “Above Ground Components”
8.3.1 Loosen pump cover bolt and remove the cover.
8.3.2 Loosen hanger pin nuts and fulcrum pin nuts fully.
8.3.3 Move the pump handle to the lowest position and insert spanner handle into the rod hanger bush.
Move the pump handle slowly upwards and guide the spanner handle into the two slots provided
at the pump head.
8.3.4
As soon as the rod hanger is hanging freely, pull out the handle carefully (horizontal).
8.3.5
Remove the fulcrum pin and the bearing bush sets from the handle.
8.3.6
Remove the hanger pin and the bearing bush sets from the rod hanger.
8.3.7
Place all small components (fulcrum pin, hanger pin, bearing bushes etc.) inside the pump head
cover to prevent that they get dirty.
47
8.4
Dismantling Threaded Pumprods
(including plunger and fishing of footvalve)
8.4.1
Take an additional pumprod and
attach the connecting tool.
8.4.2
Pull out the top rod with rod hanger
and disconnect the first joint.
8.4.3
Connect the additional pumprod
with the connecting tool and lower
the whole assembly slowly until the
plunger rests on the footvalve.
8.4.4
Take the t-bar of the connecting
tool and turn it clockwise for 3
complete revolutions.
8.4.5
The footvalve is now connected
and the removal of the whole
assembly can start.
8.4.6
Remove all pumprods “one by one”
until the plunger rod with plunger
and footvalve is released.
Make sure that all rods are neatly
placed near the pump and are in a
clean place.
8.5
Re-installing Threaded Pumprods
(including placing of footvalve)
8.5.1
Attach the footvalve to the plunger (max. 3
revolutions) and connect plunger rod and all
pumprods.
8.5.2
Instead of the top rod, connect an additional
pumprod with the connecting tool.
8.5.3
After the footvalve is sitting firm in the cone
of the footvalve receiver (cylinder), turn the
T-handle of the connecting tool anti-clockwise
for approximately 6 revolutions.
8.5.4
Lift the pumprod assembly as much that the
additional pumprod and connecting tool can
be replaced by the top rod and rod hanger.
8.5.5
Insert the spanner handle into the bush of the
rod hanger and let the assembly rest in the
two slots provided in the pump head.
48
8.6
Dismantling Hook & Eye Pumprods
(including plunger and fishing of footvalve)
8.5.6
Pull out the top rod with rod hanger and
disconnect the first joint.
8.5.7
Remove all pumprods “one by one” until the
plunger rod with plunger is released.
8.5.8
Remove plunger rod and plunger from the
last pumprod and replace them with the
fishing tool.
8.5.9
Re-install all pumprods “one by one” until the
fishing tool is resting on top of the footvalve.
8.5.10 Turn the pumprod assembly slightly so that
the hook of the fishing tool connects with the
footvalve assembly.
8.5.11 Remove all pumprods “one by one” until the
rods with fishing tool and footvalve are
released.
8.5.12 Make sure that all rods are neatly placed
near the pump and are in a clean place.
8.6
Re-installing Hook & Eye Pumprods
(including placing of footvalve)
8.6.1
Drop the plastic footvalve into the rising
main pipe.
8.6.2
Re-install plunger, plunger rod and all
pumprods.
8.6.3
Attach an additional pumprod with the
connecting tool and push the footvalve
gently in correct position.
8.6.4
Lift the pumprod assembly as much that
the additional pumprod with connecting
tool can be replaced by the top rod and
rod hanger.
8.6.5
Insert the spanner handle into the bush
of the rodhanger and let the assembly
rest in the two slots provided in the pump
head.
49
8.8
Dismantling and Re-installing FRP Pumprods
(including plunger and fishing of footvalve)
8.6.6
The advantage of FRP pumprods
(FRP = Fibre Reinforced Plastic) is
that once installed, the whole
pumprod assembly can be pulled
out of the rising main, without
disconnecting the single rods.
Therefore the time for retrieving of
a pumprod assembly is a matter of
1 or 2 minutes.
Since the total weight of an pumprod
assembly with FRP pumprods is
roughly only 1/3 of the weight of a
pumprod assembly of steel, removal
of the assembly is very easy.
8.6.7
The procedure for retrieving and placing of the footvalve depends on the set-up of the plunger
and footvalve (see also pages 48 and 49).
8.9
Re-assembling “Above Ground Components”
8.9.1 Place fulcrum pin with bearing bushes in the fulcrum bush.
8.9.2 Align the lock pins and the lugs of the bearing bushes and insert handle assembly into the pump
head. Tighten the hexagonal nuts by hand.
8.9.3
Keep pump handle horizontal and place hanger pin with bearing bushes in rod hanger assembly.
8.9.4
Align the lock pins and the lugs of the bearing bushes and move the t-bar of the handle
assembly slowly downwards, so that the rod hanger pin ends are slipping into the slots of the
handle forks. Tighten the hexagonal nuts by hand.
8.9.5
Press the handle assembly to its lowest position and release the spanner from the bush on top of
the rod hanger assembly.
8.9.6
Tighten the fulcrum pin- and rodhanger pin nuts securely with the spanner.
8.9.7
Operate the pump and check the discharge and leakage.
8.9.8
Attach the pump cover and secure it by tightening the cover bolt.
(For more information see also No. 6.2 Installation of “Above Ground Components”.)
50
9.0 Repair of Handpump
Major interventions such as the replacement of the rising main assembly or retrieving of dropped
components are beyond the capacity of the handpump caretaker and therefore will need to be
carried out by a skilled mechanic.
9.1
Removal of the Rising main
There are several reasons that makes it necessary to remove the rising main:
An excessive leakage that cannot be attributed to a leaking footvalve (bobbin or o-ring),
A disconnected riser pipe due to poor quality of the pipe joints,
Dropped components that have jammed inside the rising main and cannot be fished out,
The cylinder is suspected to need replacement.
9.1.1 Cutting the Rising main
Traditionally when the rising main
was removed it was cut into
manageable lengths of 2 to 3 pipe
lengths or 6 to 9 m (see picture).
Cutting of the rising main meant
that a large number of joints had
to be re-made upon replacement.
If suitable double sockets were
not available, joints were formed
by warming the PVC-U pipes in a
fire. It is very important that joints
in the PVC-U rising main are
correctly made to ensure a
sustainable long-term repair (see also 5.4 Important Information for Jointing PVC-U Pipes).
9.1.2 Pulling out the whole Rising main
To minimise the number of joints that need to be made during a repair the rising main is
removed from the borehole in one length without making any cuts. The problem is identified and
repaired before replacing the rising main back in the borehole, once again in one length.
During removal of the rising main assembly in one length the joints will come under
considerable stress. This procedure should only be attempted if it is known that the PVC-U
joints were correctly made during the installation, otherwise there is a danger that a joint may
break and could cause injury.
In addition to the tools needed for pump repair the additional resources needed to withdraw
the rising main are:
At least 8 people, preferably including all or some of the pump caretakers.
Poles with forked ends for supporting the rising main when pulled out. The number of poles
should be equal to the number of riser pipe lengths in the installation and their length should
be approximately 3.5 to 4m.
A guide rope of at least 10 m length, which is connected to the steel cone and is used for
leading the tilting rising main into the right direction.
A cleared area is required next to the well, long enough to accommodate the complete rising
main when laid down immediately after withdrawal. In this place, no disturbance should take
place during the repair and the curing time of the new joints (12 hours).
51
The procedure is:
a.) Remove the footvalve. This may not be possible if there are components stuck inside the
rising main. It is still possible to remove the rising main in one piece but extra care must be
taken as the weight of water and components will make the control of the rising main as it
comes out of the borehole much more difficult.
b.) Remove the pump head.
c.) Tie the guide rope to the cone
plate.
d.) Start to pull the rising main out
of the borehole by pulling the two
ends of the support rope and the
pipe. The guide rope is used to
control the free end of the pipe.
As the rising main comes out of
the borehole start to bend it in the
direction chosen for it to be laid
down.
Using the shorter forked poles to
start to take the weight of the
pipes at the same time to keeping the radius of the bend as long as possible.
e.) As the pipe continues to be pulled out the longer forked poles are used to support the free
end of the pipe which should be
kept up and the pipe horizontal
so that the bend is at least
three pipes long.
If it has not been possible to
remove the footvalve the open
end of the pipe should be lowered
just enough to drain the water out
so that the weight is reduced.
The shorter poles at the borehole
end of the pipe need to be held
off the ground to allow them to be
moved easily along the line of
removal.
The longer poles in the middle
and free end can be allowed to rest on the ground to take the weight and stabilise the pipe.
f.)
If at any time a joint is appears to be weak (e.g. there is evidence of burning as in a home
made joint) the pipe should be carefully supported and cut at the suspect joint.
Do not try to bend a weak joint.
g.) When the cylinder and suction pipe are reached they are carefully withdrawn, making sure
to maintain control of the whole pipe. The whole pipe length can now be laid down.
h.) After the necessary repairs have been carried out the whole length of pipe must be carefully
cleaned before replacement.
Before replacing the Rising main pipe the borehole should be disinfected as described under
4.9 (Disinfecting the Well).
i.)
Replacing the pipe is the reversal of removal. Some difficulty may be experienced inserting
the cylinder and suction pipe, as some force has to be applied to bend the Rising main pipe
sufficiently to enter the borehole.
52
Under normal circumstances, the preparation time for the procedure described above will take
approximately one hour. After that, the time for withdrawal will take between 15 to 30 minutes
and the time for the replacement of the rising main assembly should take not longer than 10 to
20 minutes.
If a number of pumprods are stuck inside the rising main (broken “hook & eye components) and
all fishing attempts to retrieve them have failed, it is advisable not to withdraw the rising main in
one piece. It is better to use the method described under 9.1.1 (Cutting the Rising main).
A different system for supporting
the withdrawn rising main pipe is
shown in the picture beside.
Heavy logs are placed in the
ground and are acting as a
scaffolding, strong enough to
accommodate one person.
The support for the withdrawn
rising main pipe is made by the
persons on the scaffoldings and
in the trees nearby.
9.2
Repair of the Rising main pipe
Whatever intervention is made, it is most important that the overall length of the rising main
pipe must not be changed. Any change in the length of the rising main pipe would automatically
affect the exact position of the plunger in the pump cylinder.
Unless an obstruction can be removed by tipping the pipe up, which is very unlikely, or there
is leakage from a joint that can be reconnected, it will be necessary to cut the rising main and
repair it with a socket.
9.2.1 Repair with Double Socket
The choice of where to cut
depends upon the repair that
needs to be carried out. If there
is a hole in the pipe, which may
be caused by the internal
rubbing of a rod joint (due to a
missing rod centraliser), the pipe
will need to be cut in two places
one on each side of the hole.
For this purpose a “Repair piece”
with bell-ends at both sides will
be needed, see sketch beside.
(the technical drawing for
manufacturing repair sockets
can be found in Annex VII.)
Cut the affected portion in such a way, that the total length of the rising main remains the same
after jointing the repair piece.
53
9.2.2 Repair with Single Socket
If the problem only requires access
to the inside of the rising main or
cylinder, such as the removal of
an obstruction, then the pipe only
needs to be cut in one place.
The location of the cut depends
upon the problem to be resolved.
A single socket is a straight piece
of pipe 230 mm long with an
internal diameter that just fits over
the outside of the rising main pipe
(see drawing C2438 in Annex VII).
Each end of the pipe at the joint
must be marked at 115 mm to
ensure that the single socket is equally distributed over the joint. The jointing of PVC pipe should
be done as recommended in 5.4 (Important Information for Jointing PVC-U Pipes).
If a length of pipe has had to be cut out, for example it has a hole in it, it must be replaced by a
pipe of equal length and two single socket joints made. The shortest length of a repair should be
300 mm to ensure that the joints
on each side are adequate.
Do not be tempted to make a
patch with a piece of pipe and
stick it on using solvent cement.
It will not last and the rod
centraliser will be quickly
damaged as it rubs past the
inside of the hole.
After the rising main pipe is
back in the borehole, the exact
lengths of the pumprod needs
to be checked and adjusted as
required (see also 6.2.11).
The reason for checking the
equal lengths of pumprod and
rising main, is because this
length is important for the exact
position of the plunger inside the
pump cylinder.
If the pumprod assembly is too long or too short compared to the rising main pipe, the plunger
will either leave the plunger sleeve or hit the footvalve at every stroke during the operation of the
pump. In both cases the plunger or the footvalve will be destroyed over a very short period of
time.
54
9.3
Fishing of Dropped Handpump Parts
During installation or maintenance activities, handpump components might fall into the well
causing an obstruction, which immobilises the pump.
Retrieving dropped components like a rising main from a Dug well is not a problem, whereas
fishing of dropped parts in a casing pipe of a Borehole can be a difficult and time consuming
task.
In some cases, items inside the Rising main pipe may be extracted by removing the whole
rising main and cutting it to gain access to the obstruction (as described under 9.1.1).
In other cases something relatively simple can be made by the Area Mechanic to suit the
object causing the obstruction.
For example a “U-seal” that has rolled off the plunger and is left in the cylinder or rising main
may be fished using a simple wire hook on a string. In the case of a “U-seal” left inside the
rising main it is important not to try to fish the footvalve. If this is attempted the “U-seal” often
causes the footvalve to jam inside the rising main pipe, making it necessary to remove the
whole rising main assembly with the rods inside. Some ingenuity is required on the part of the
Area Mechanic to deal with each situation as it arises.
A number of special tools “Fishing Tools” have been developed, in order to assist any fishing
attempts of dropped handpump components. However, often these tools are not available or
do not quite fit the problem at hand so more informal solutions need to be found. This mostly
depends upon the ingenuity of the Area Mechanic.
The assembly drawings of the “Fishing tools” can be found in Annex VI.
Detail drawings for manufacturing of the developed fishing tools are available on request.
10.0 Recording of Interventions
It is advisable to collect and record any data of a well, starting from digging or drilling, platform
construction, installation of a handpump including all maintenance and repair interventions during
the lifetime of the handpump and the well (like a “log-book” on a ship).
Besides Installation and Monitoring details, make the necessary entries of Maintenance and
Repair in the documents of each pump. The information to be recorded will include date of
breakdown, date of repair, nature of complaint, parts replaced and kind of repair or any other
important observations. (see also “Examples for Recording of Interventions” in Annex V).
55
Annex I
Trouble Shooting Chart for AFRIDEV Handpumps
56
57
Annex II
List of Spare Parts for AFRIDEV Handpumps
58
59
60
Annex III
Replacement Interval of AFRIDEV Wearing Parts
61
62
Annex IV
Correct Storage of AFRIDEV Handpump Components
63
Correct Storage of AFRIDEV Handpump Components
In order to keep the Afridev Handpump components in good condition, special care has to be taken for
storage of these spare parts. The Afridev Handpump components are made of different materials
groups, like:
a) Metal parts and assemblies
b) Rubber components
c) Plastic components
d) Chemical liquids
These specific material types require different storage conditions, which are described below.
Metal parts and assemblies
All major assemblies are treated against corrosion by “hot dip galvanizing”, which gives a good
protection for hot and humid conditions. For storing these assemblies (Pump head, Cover, Handle Pump
stands etc.), care should be taken that the corrosion protection (zinc) on the surfaces will not be
scratched.
Electroplated components do not give a long lasting corrosion protection, therefore components like
Fulcrum- and Hanger pins, Spanner, Bolts and Nuts etc., should be stored in a dry place.
Long and flexible components like all (metallic) Pumprods need to be stored on a flat surface, so that no
bending takes place (bent rods are mostly the cause of perforated Riser pipes).
Stainless Steel components and Brass components do not require special storage conditions.
Rubber components
Nitrile and natural Rubber components are sensitive against “Ultra Violet Rays” and hot conditions. It is
not allowed to store these materials in a place, where sunlight has access. The flexible rubber
components like O-Rings, U-Seal, Cup seals, Bobbin Pumprod centralisers etc. should be kept in a
safe place, so that no heavy materials can be placed on top of them. Rubber components that are badly
bent or squashed for a long time (in a hot place) will not be able to recover and therefore cannot be
used anymore.
Thick walled rubber components like Compression cone or Rising main Centralisers are not so critical
products for storage.
Special care has to be taken that rubber products are not stored in places where chemical substances
are kept (also Oil can be harmful).
Plastic components
Plastic components, like rubber products have a very low resistance against “Ultra Violet Rays”.
Especially PVC-U pipes are getting brittle when stored in the sunlight and cracking of Riser pipes are
mostly the cause of wrong storage.
Hot storing places are also not recommendable, whereas humid places are not harmful.
Components like Bearing bushes
and Footvalve receivers are not
critical products for storage, apart
from direct sunlight.
Special care has to be taken for
correct placing of Riser pipes
(especially pipes with bell ends).
Besides a flat place, a careful
stacking is required and the stack
is not allowed to be too high,
because the heavy weight will
squash the lowest pipes
(see picture as an example for
good stacking).
64
Chemical substances
Cleaning fluid and Solvent cement for jointing Rising main pipes should not be stored in large
quantities. It is advisable to procure solvent cement locally, shortly before pump installation takes place.
These substances should be kept in a cool and dry place, which is in most stores not available. Since
the solvent cement keeps its liquidity only for a short period of time, never procure large quantities (for
financial reasons). As soon as the solvent cement is not running smoothly it is not fit anymore to make a
good bonding of pipe joints (and should be disposed).
65
Annex V
Examples for Recording of Interventions
a)
b)
c)
Installation Card
Maintenance Card
Monitoring Card
66
67
68
69
Annex VI
Drawings of Fishing Tools for dropped Handpump Parts
a)
b)
c)
For Fishing disconnected Pumprods
For Fishing broken Pumprods
For Fishing disconnected or broken Riser Pipes
Please note: for all detail drawings please contact SKAT (see address on first page).
70
71
72
73
Annex VII
Technical Drawings of Repair Sockets
d) Repair socket C2438 (straight socket),
e) Repair socket C2439 (socket with bell-ends)
74
75
76